We report a patient who ingested about 13 g of Padan SG, a cartap-containing pesticide. After ingestion, the patient developed multiple seizures and dyspnea and lost consciousness. The patient did not recover and died on the fifth hospital day despite treatment at the early stage of poisoning. The cause of death was multisystem organ failure. Results of toxicological analysis were as follows: concentrations of nereistoxin (cartap metabolite) were 10.6 microg/mL in plasma, 18.2 microg/mL in urine, and 2.6 mg/mL in gastric fluid. Results of drug screening of urine by Triage DOA Panels and using an organophosphate detection kit were negative.